Biotechnology And gene manipulation Biotechnology Using organisms and

Biotechnology And gene manipulation

Biotechnology • Using organisms and biological processes for human benefit • Very old – Fermentation to produce alcohol and bread • New techniques allow manipulation at the molecular level • Some biotechnology controversial

Gene technology • Much of modern biotechnology related to gene technologies • Also known as genetic engineering • Like mechanical engineers there are tools

Gene Technology - Tools • • • Cut DNA Join/splice DNA fragments Amplify DNA Sort DNA Probe for genes Sequence DNA

Cut DNA • Restriction enzymes or restriction endonucleases • Cut DNA into fragments in a controlled manner • Cuts occur at specific sites – Recognition sites

Restriction enzymes • Naturally occurring in bacteria – Part of their defence system – Destroy foreign DNA by cutting it up • Named after the bacteria they are found in – Escherichia coli Eco. R 1

Restriction enzymes • Examples

Restriction enzymes

DNA ligases • Join DNA fragments together • Found in cells – Repair damaged DNA • Join complementary sticky ends (created by restriction enzymes)

Recombinant DNA • Combine a gene from one species into the DNA of another species • So what’s the big deal?

GM • Genetically Modified crops • Add beneficial gene from one species of plant into an agricultural plant – Disease resistance – Natural insecticide • Controversial

Amplifying DNA • PCR – Polymerase Chain Reaction – Uses DNA polymerase enzyme to create copies of DNA – Single strand can be copied millions of times • amplified

PCR Cycle • DNA + DNA polymerase + primer + nucleotides + buffer • DNA heated to 95 o. C – DNA denatures – splits into separate strands • DNA cooled to 50 -55 o. C – Primers bind to opposite ends of DNA • DNA heated to 72 o. C – New DNA strands synthesised

Sorting DNA • Gel electrophoresis • DNA fragments separated according to – Size – Charge • UV fluorescing dye bound to fragments • Autoradiograph – Photo taken under UV light